Compatibility Guidance

Compatibility Disclaimer

GuideMyTank compatibility scores are designed to support better aquarium planning, not replace careful observation or responsible husbandry.

How compatibility scores work

The GuideMyTank compatibility score estimates how likely two species are to coexist based on known aquarium husbandry factors, including temperature overlap, pH overlap, temperament, aggression risk, schooling needs, predation risk, and minimum tank size requirements.

Recommendations, not guarantees

A high score does not guarantee success, and a caution result does not always mean a pairing is impossible. Compatibility should be used as a planning signal alongside tank size, aquascape, filtration, stocking level, water quality, and the specific behavior of the fish involved.

Fish behavior can vary

Individual fish may behave differently from typical species profiles. Age, sex, breeding behavior, territory, stress, prior experiences, and tank conditions can all influence aggression, hiding, feeding, and social behavior.

Best practices for new tankmates

  • Research both species before purchase.
  • Quarantine new fish when possible.
  • Match temperature, pH, hardness, and tank size needs.
  • Provide hiding places, visual breaks, and swimming space.
  • Introduce new tankmates slowly and observe closely.
  • Have a backup plan if aggression or stress appears.

Transparent recommendation philosophy

GuideMyTank aims to make aquarium recommendations transparent and understandable. Compatibility results include reasoning whenever possible so aquarists can see why a pairing may be recommended, flagged for caution, or marked incompatible.

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